Burglar alarm switch



March 14,1939. c F. SCHULTZ 2,150,873

' BURGLAR ALARM SWITCH Filed July 1, 1957 Tz'y.]

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6K]? SCIZuZZZ Patented Mar. 14, 1939 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to an improved electrical burglar alarm.

The object of this invention is to provide a switch adapted to be operated by the opening of a closure such as a door to automatically close a circuit to a signal which may be remotely place-d to warn the owner that his property is being entered, without warning the trespasser.

A further object of this invention is to provide a swinging plate which may be moved into a position to hold the circuit open during the daytime when it is more convenient to have the signal disconnected.

Other objects and advantages of the invention will hereafter become more fully apparent from the following specification of which the drawing forms a part, and wherein:--

Figure 1 is a top plan view of the invention mounted in a door frame, the door frame and the 2 door being shown in section, and broken away,

Figure 2 is a vertical sectional view of the same with a battery and signal shown diagrammatically, and

Figure 3 is an elevational view on the line 33 25 of Figure 2.

Referring more particularly to the drawing wherein like reference characters designate like or corresponding parts in the different views, l0 designates a portion of a door frame and II a 30 portion of a door hinged at l2 to frame In. Frame I0 is provided with a recess I3 to receive the invention which comprises a casing l4 provided with an outturned flange |5 at its open end l6. A face plate I! covers the opening l6 and is 35 shaped to fit flush with flange I5. Flange I5 and plate I1 are countersunk in frame It] and secured together and to the frame l0 by nails l8 or like fastenings.

Mounted within casing M by means of L 40 shaped brackets H! are the transverse portions and 2|. Secured in portion 20 by brackets 22 is an insulated plug 23 provided with contact points 24 and 25 forming one contact member. Connected to the points 24 and 25 are wires 26 and 5 21 respectively which lead to the opposite poles of a battery 28 or the like.

Partition 2| is provided with an opening 29 and an annular flange 30 forming a guide for the cylindrical insulating plug 3| which is slid- 50 ably mounted therein and which is provided with the contact points 32 and 33 to engage points 24 and 25 respectively. Points 32 and 33 are connected to wires 34 and 35 respectively which lead to a bell 36 to form with plug 3| the second con- 55 tact member.

Secured to plug 3| by means of a nut and bolt 31 is the hooked end 39 of a plunger 38. The shank of plunger 38 extends through openings 46; in plates I1, partitions 28 and 2| and is slidably mounted therein. The exposed end of plunger ,5 38 is provided with a head 4| to be engaged by the edge of door I l which abuts frame ID as seen in Figures 1 and 2. Pivotally mounted on plate I! by a bolt 42 is a guard plate 43 which is spaced from plate H by a sleeve 44. Plate 43 as 10 seen in Figure 3 is held in either one of the two positions as shown in full and dotted lines by pin 45 so that when it is desired to disconnect the alarm 36 plate 43 is moved to its dotted line position to hold plunger 38 retracted regardless of 16 whether the door II is open or shut. By swinging plate 43 to its full line position plunger 44 is released to allow plug 3| to be operated. Mounted between plate 2| and the hooked end 39 of plunger 38 is a spring 46 which projects plug 20 3| forward to cause points 32 and 33 to engage points 24 and 25 respectively to close the circuit between the bell 36 and battery 28 when door H is opened releasing plunger 38 from its retracted position. 25

Bell 36 and battery 28 could obviously be replaced by any other suitable signal such as a light and by any other suitable source of current without affecting the invention.

Guard plate 43 besides eliminating the neces- 30 sity of a switch to disconnect the current also holds plunger 38 in a retracted position so that the invention will not be damaged or worn by the frequent movement of door H which might occur during the day. 35

From the foregoing it will be obvious that when door I is closed and plate 43 is in the position as shown in full lines in Figure 3 that the device is set so that if door H is opened plunger head 4| Will be released to allow spring 46 to project plunger 38 and plug 3| forward to cause points 32 and 33 to engage points 24 and 25 respectively. This will close the circuit through battery 28 and bell 36 to energize bell 36 which may be placed in any position to warn a particular person that an inclosure is being unlawfully entered.

It is to be understood that only the preferred embodiment of the invention has been shown and described the right being reserved to make such changes as do not depart from the spirit 50 and scope of the invention as claimed.

I claim as my invention:

In a door actuated alarm, a casing adapted to be mounted in a recess in a door jamb, partitions rigidly mounted transversely of and in members into engagement to close a circuit from a source of electric current to a signal, said plunger adapted to be engaged by the hinged edge of a door when closed to retract said sliding contact to open the circuit, and a swinging keeper pivotally mounted on the outer side of said plate and in spaced relationship thereto and movable into engagement with the outer end of said plunger, when in a fully retracted position to maintain said switch in an open position.

CHARLIE F. SCHULTZ. 

